1. Field Of The Invention
This invention relates to an improved mounting for a compressor and drive motor on an air receiving tank and more particularly to a ratchet or hold-down mechanism for a motor which is pivotally attached to a base of the compressor.
2. Description Of The Prior Art
Portable and stationary air compressors are used for many applications, including operating pressure feed tanks, spray guns, caulking guns, air brushes, sand blasters, pneumatic tools, tire inflaters, etc. Air compressors for these applications generally comprise a cylindrical air receiving tank, a belt-driven compressor, and a motor. In prior art air compressors, a mounting platform typically is welded either to the upper side of a horizontally-oriented tank or to the top of a vertically-oriented tank. The compressor and the motor are mounted on the platform, and a drive belt is provided to interconnect pulleys on the rotor and the compressor. The motor generally is bolted through slots in the mounting platform, which allows for adjustment of the motor position toward and away from the compressor to adjust belt tension. Since the air receiving tank must withstand a high internal gas pressure, highly skilled welders are required for welding the mounting platform onto the tank to avoid weakening the tank at the welds. Also, in this prior art construction, tension on the drive belt applies bending forces to the mounting platform which, in turn, stress the tank at the welds. These stresses fluctuate with changes in the compressor load, since both the motor and the compressor are rigidly bolted to separate locations on the mounting platform.
In a typical prior art air compressor, the pulley mounted on the compressor is of a considerably larger diameter than the pulley on the motor so that the compressor is driven at a much lower speed than the motor. In order to prevent belt slippage when the motor and the compressor are both rigidly attached to the mounting platform, a substantial spacing is required between the motor and the compressor to provide sufficient wrap of the belt around the small motor pulley.